One-piece duct and method of making it

ABSTRACT

A one-piece molded duct and method of making it. The duct comprises two halves joined together by an integral bendable portion. The bendable portion comprises a fluid-tight hinge about which the duct halves may be pivoted into opposed and abutted position to form the finished duct. Means are provided to maintain the halves in opposed and abutted position. Each duct half may be provided with baffle means which assume a proper relationship when the duct halves are in their opposed and abutted position.

United States Patent William ll. Yake Connersville, Ind.

J une 1 9, 1969 Jan. 5, 1971 1 Design and Manufacturing Corporation Connersville, Ind.

a corporation of Indiana Inventor Appl. No. Filed Patented Assignee ONE-PIECE DUCT AND METHOD OF MAKING IT 5 Claims, 11 Drawing Figs.

Int. Cl..- F151! 1/04 Field ol'Search 138/37, 44;

137/1; 1 10/(Considered); 48/(Considered); 25l/(Considered); 302/(Considered); 52/219, 245

[56] References Cited UNITED STATES PATENTS 1,857,862 5/1932 Page l38/44X 2,224,208 12/1940 Acer 138/37 2,371 ,202 3/1945 Whitesel Primary Examiner- Herbert F. Ross Attorney-Melville, Strasser, Foster & Hofi'man PATENTEDJIVAN 5L9?! j $552,443

SHEET 3 BF 3 INVENTOR/S 94 WILLIAM H; YAKE ATTOR NEYS 1. Field ofthelnvention I The invention relates to a duct structure and method of making it. More particularly, the invention relates to a onepiece duct structure comprising two opposed and abutted halves joined by an integralhin'ge'portion. e 1.,

2. Description of the Prior Art -The'duct structure of the present inventionand the method of making it; are substantially unlimited in their application. However, for purposes of an exemplary showing, the duct structurewill be described in its application as'a part of the drying blower system of a dishwashing machine.

In its usual form, an automatic dishwasher comprises a vat having a front or top access opening. Generally, upper and lower racks for tableware are located in the vat. The vatwill have a sump-formed in-its bottom and therewill be'a motor mounted below the sumpwhich drives one or more'pumps, and in many instances an impeller for showering the tableware with detergent solution or rinse water. In many such machines, a pump isemployed of such character as to result in circulating the water within the vat when the motor is driven in one direction, but to "exhaust the water or drain thevat when the 7 motor is driven in'the opposite direction.

Such machines generally contain one or more solenoid operated valves; they are usually provided with a door operated switch which will permit operations only when the door is closed; they frequently contain'a switch-operated electric heater, and sometimes electrically operateddevices for delivering to the vat measured increments of detergent sub stance and the like. These and other operating instrumentalities are well known with respect to dishwashing rnachines and do not constitute a part of the present invention. 7

Automatic dishwashers are arrangedv to carry on a plurality of steps or operationsin predetermined sequences. The vari ous' sequences of operations are generally'referred to as cycles." The'cyeles are controlled by timer means, of which various varietiesare known. I v g Many of the cycles will usually contain a drying step "wherein air from outside, the vat is introduced into the vat by complex design; have been expensive to manufacture; and

have offered difficulties with respect to renderingrtheductsthemselves watertight.

The presentinvention provides a vastly'simplified one-piece duct structure which is easy and inexpensiveto' manufacture and install. In addition, the duct structure of the present invem tion is watertight along its top edge by virtueofits integral hinge construction. a

SUMMARYQFYTHEINVENTIGN' The present invention deals witht-a duct structure: anda method of making it. In accordance" with the present invention 65' a duct structure may be molded in the form of a unitary open structure comprising two .halves connected; by an": integral bendable portion. After the. molding operatiomthe'strueturemay be folded uponitself-along the integral bendable portion, which servesas a hinge.- In foldedcondition', the two halves lie in opposed, abutting relationship and fonn the finished-duct:

structure.

When the duct iszmounted.in'ritsfinalpositienon the device to which it is-to be affixed, themounting:meanswillholdtheduct halves in their=opposed and abuttingposition: One-half of 75 L exit of water through air'inlet openings. in theqvat. However, suchduct means have generally been multipiece structures of the .duct structure may be provided with retaining boss means while the other half is provided with retaining depression means. The boss means may have a snap fit with respect to the depression means so that the duct structure may assume and maintain final folded condition prior to mounting.

When desired, the duct halves may be provided with baffle means which assume a proper relationship when the baffle structure is in its final folded form.

Preferably, the structureis made of moldable material having good bending or hinging characteristics. Polypropylene, for example, has been found to be an excellent material from which to mold the duct of the present invention, particularly by virtue of its hinging or bending characteristics.

,BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 and2 are respectively semidiagrammatic side and front elevations of a dishwashing'machine vat illustrating an embodiment of the blower and duct assembly of the present invention. 7

FIG. 3 is a plan view of the duct structure of the present invention in its molded, but unfolded form.

along the sectionslines 7-7; and 8-8 in FIG. 5.

FIG. 9 is an elevational'view of a mounting plate for the blower assembly;

FIG. 10 is an elevational view of the blower housing. FIG. 11 is a cross-sectional view taken along the section line 1 l-l 1 of FIG. 1 and. illustrating the entire duct-blower as- 'sembly.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIGS. 1 and 2 are semidiagrammatic representations of a dishwasher vat and like parts have been given like index nu metals. The vat is' generally indicated at 1 Although the invention is not so-limited, for purposes-of an exemplary showing, the vat is illustrated as being of the front opening type.

Thevat 1 comprises a top wall 2 a back wall 3, sidewalls 4' and Sand a front access opening generally indicated at 6. Thebottomof the vat is provided with a sump 7 to which a motor and pump assembly is affixed, as is diagrammatically represented at 8.

It will be understood by one skilled in the art that the vat will be surrounded by an appropriate exterior case; will be provided with a closure means for the access opening 6', and

will contain tableware racks, fluid agitating of spraying means and the like, none of which-are'sh'own but all of which are well knowttin the art.

FIGS. 1 and 2 illustrate the duct-blower assembly of the present invention. While the location of this assembly is primarily'a matter of design-choice,;for purposes of anexemplary'illustration it is shown as locatedon the'side'of the sump 7' near the rear of the vat. The assembly broadly comprises a mounting plate 9' with amotor lolocatedon one side thereof and ahousing 11 located onthe other. The housing 11 surrounds'a blower or impeller means (not shown) of any suitable type. The housing II is provided'with arrinlet opening 12 for outside air. The outsideair is drawn in by the impeller and forcedcthrough the housing": and openings in the mounting plate 9and the wall ofthe sump 7'td* the duct means 13' mounted; on the inside surface of the sump. From the duct means, the'outside air may passinto the-vat for purposes of dryingthe tableware. As will be described hereinafter, the duct' 13 permits the passagei of air therethr'ough, but is providedwith appropriate baffle means to' pre'vent' the exit of water from the sump. The various details of the duct and the duct-blower assembly will nowbe described.

FIGS. 3 and 4'illustrate the duct, generally indicated at 13,

inits'as-molded'fornr. FIG. 3 is-a plan view'of the inside surfaces of the duct structure 13, while FIG. 4 is an end view thereof, as seen from the right in FIG. 3.

The duct 13 comprises two halves, generally indicated at 14 and 15 joined by a bendable or hinge portion 16.

The duct half 14 is most clearly seen in FIGS. 3, 4 and 6. FIG. 6 illustrates the rear surface of the duct in its folded form, thereby showing the exterior surface of the duct half 14. The duct half 14 comprises an elongated, substantially rectangular portion 17, having end edges 17a and 17b and being provided along its longitudinal edges with rearwardly extending ribs 18 and 19.

The planar surface 17 of the duct half 13 has two rectangular openings 20 and 21 which comprise openings for the passage of air. There are also two large perforations 22 and 23 and two small perforations 24 and 25, the purpose of which will be fully described hereinafter.

The inside surface of the duct half 13 is illustrated in FIGS. 3 and 4. The air openings 20 and 21 are collectively sur rounded by integral inwardly extending flanges 26, 27, 28 and 29. It will be noted (FIG. 4) that all of the flanges 26, 27 and 28 extend inwardly to the same extent, the flange 29 extending inwardly to a slightly greater degree.

The lower inside surface of the duct half 13 has an inwardly extending flange 30 supported by a plurality of triangular braces 31 through 34. The triangular brace members 31 and 34 are, respectively, coplanar with and constitute extensions of the flanges 28 and 27.

Between the longitudinally extending flanges 29 and 30 there are two additional flanges or webs 35 and 36 having on their innermost edges notches 37 and 38 respectively. The purposes of these notches will be described more fully hereinafter.

The lowermost corners of the duct half 13 have inwardly extending lugs 39 and 40. The lug 39 has a top surface 39a which is substantially parallel to the planar portion 17 of the duct half 13. The lug 39 has a surface 39b which lies at an angle of about 45 to the planar portion 17. The lowermost edge of the lug 39 is undercut as at 41.

The lug 40 is substantially identical to the lug 39 having surfaces 40a and 40b corresponding to surfaces 390 and 39b. The lowermost edge of the lug 40 is undercut as at 42. As will be described hereinafter, the lugs 39 and 40 cooperate with appropriately configured depressions or pockets on the duct half 15 to maintain the duct halves in their folded condition.

The duct half 15 is illustrated in FIGS. 3, 4 and 5. FIG. is a front elevational view of the duct in its folded and final form, and thus illustrates the exterior surface of the duct half 15. FIG. 3 illustrates the interior surface of this duct half.

The duct half comprises a planar portion 43 having rearwardly extending side elements 44 and 45. Above the planar portion 43 there is a rearwardly slanting portion 46 which extends to the hinge portion 16.

Projecting forwardly from the planar portion 43 there is a hoodlike element 47, the top portion of which curves rearwardly to the planar portion 43. The hoodlike element 47 has sidewalls 48 and 49 which extend downwardly to the bottom edge of the duct half 15. As is most clearly shown in FIGS. 3 and 4, the bottommost edge of the hoodlike element 47 has a flange 50 which extends rearwardly between the sidewalls 48 and 49. Integral triangular brace members for the flange 50 are shown at 51 and 52.

On either side of the hoodlike element 47, the planar portion 43 has perforations, indicated at 53 and 54.

Referring particularly to FIGS. 3 and 4, it will be seen that the inside surface of the planar portion 43 of the duct half 15 is provided with rearwardly projecting reinforcing ribs. On such rib 55 extends along the top. Ribs 56 and 57 extend along the sides, inside the rearwardly extending side elements 45 and 44, respectively. The lower edges are provided with ribs 58 and 59, while ribs 60 and 61 constitute rearward extensions of the sidewalls 48 and 49 of the hoodlike element 47. At the top of the hoodlike element 47, the inside surface of the duct half 15 is provided with an additional rib 62, parallel to the rib 55 and joined thereto by triangular reinforcements 63 through 67.

The perforations 53 and 54 are surrounded on the inside surface of the duct half 15 by substantially circular ribs 68 and 69, respectively. Above these ribs there are additional arcuate ribs 70 and 71 defining U-shaped areas 72 and 73, respectively, on the inside surface of the planar portion 43.

As is most clearly seen in FIG. 3, additional riblike elements 74 and 75 extend downwardly from the circular ribs 68 and 69, respectively. The lowermost portion 74a of the rib 74 slopes at an angle of about 45 toward the inside surface of the planar portion 43. The rib 75 has a similarly sloped portion 75a.

As will be seen from FIGS. 3 and 4, the rib 59 along the bottom right-hand edge of the duct half 15 is undercut as at 59a. The undercut 59a and the slanted surface 74a form a pocket for the receipt of the lug 40 on the duct half 14. The undercut 42 on the lug 40 cooperates with the undercut 59a on the rib 59 while the slanted surface 40b on the lug 40 cooperates with the slanted surface 74a on the rib 74 to provide a snap fit between the lug and the pocket. The rib 58 on the bottom lefthand side of the duct 15 is similarly'undercut and cooperates with the adjacent slanted surface 75a of the rib 75 to receive the lug 39 on the duct half 14 in a similar snap fit. Thus, the duct half 14 may be pivoted downwardly about the hinge line 16 into opposing and abutting relationship with the duct half 15 and will be maintained in opposing and abutting relationship by the above-described lug-pocket snap fit.

When the duct structure has been so folded upon itself, it forms the completed duct as shown in FIGS. 5 and 6. While dimensions do not constitute a limitation on the present invention, when the duct structure is molded of polypropylene it has been found that wall and rib thicknesses of about .062 inches will provide adequate strength. Under these circumstances the hinge portion 16 may have a thickness of about .0 l 2 inches.

FIGS. 7 and 8 are cross-sectional views through the completed duct illustrating the relationship of the parts. Like parts have been given like index numerals.

Referring first to FIGS. 6, 7 and 8, it will be noted that the longitudinally extending ribs 18 and 19 on the rear surface of the duct half 14 cooperate with the rearwardly extending side elements 44 and 45 on the duct half 15 to form a flangelike frame about the planar surface 17. Affixed to this planar surface (as by gluing or the like) there will be a rectangular gasket 76, the edge portions of which will abut the frame 18 19, 44 45. The resilient gasket 76 will have openings and perforations extending therethrough, corresponding to the openings 20 and 21 and the perforations 22 through 25 in the duct half 14.

From FIGS. 7 and 8 it will be seen that when the duct structure is in its final form the rib 62 on the duct half 15 will overlie the rib 26 on the duct half 15. Air from the outside will pass through the openings in the gasket 76 (one of which is shown at 76a) and through the openings 20 and 21 in the duct half 14. From there, the air will pass through the baffle system formed by rib 29, flange 50 and rib 30. The air can exit the duct into the dishwasher vat through the opening formed between the rib 30 and the flange 50.

From FIG. 8, it will be noted that the edge of the rearwardly extending flange 50 is located in the notch 38 of the rib or web member 36. The edge of the flange 50 will similarly be located in the notch 37 of the web or rib 35. This will add additional support for the flange 50.

As thus far described, it will be noted that the duct structure, in its final folded form, provides a baffle system having both horizontal members 29, 30 and 50 and vertical members 35 and 36. While this will permit free passage of air, sprayed or splashed fluid from within the vat during the washing or rinsing cycles will not pass through this baffle system to the exterior of the vat.

It will also be noted that when the baffle structure is in its final form, the perforations 24 and 25 in the baffle half 14 will be coaxial with the perforations 54 and 53, respectively, in the bolts or screws, as will be described hereinafter. It will further be noted that the perforations 22 and 23 in the duct half 14 will be in alignment with the U-shaped areas 73 and 72, respectively in the duct half 15. The reasons for such alignment will be discussed in detail hereinafter.

FIG. 9 illustrates the mounting plate-9. (see FIGS. 1 and 2) adapted to be affixed .to the exterior of the sump portion of the vat and to have the motor and the blower or impeller housing 11 mounted thereon.

The mounting plate 9 has a large central opening 77 adapted to receive an impeller means. Additional perforations 78 through 83 are provided to enable attachment of the blower housing to the mounting plate. The mounting plate also has two large, elongated openings 84 and 85 which are adapted to correspond to and be in alignment with similar openings in the vat or sump side and duct openings and 21. Finally, the mounting plate 9 is provided with perforations 86 through 89 which also are adapted to be coaxial with similar perforations in the vat or sump side and duct perforations 22 through 25, respectively.

FIG. 10 is an elevational ,view of the blower or impeller housing 11. The side of the housing not shown is open and is intended to be enclosed by the mounting plate 9. The housing 11, which maybe formed or molded of metal, plastic, hard rubber or the like has a portion 116 adapted to enclose the impeller. The portion 110 has the opening 12 through which the impeller may draw outside air. An offcenter portion 11b is adapted to conduct air from the impeller to the portion 110 which overlies the openings 84and' 85 in the mounting plate, the equivalent openings in the vat or sump side (not shown) and the duct openings 20 and 21. The housing 11 has a peripheral flange 90 adapted to abut in airtight fashion the adjacent surface of the mounting plate 9. Gasket means (not shown) may be located between the peripheral flange 90 and the mounting plate 9. The housing 11 has a plurality of perforated bosses 91 through 96, the perforations of which are adapted to be coaxial with the perforations 78 through 83on the mounting plate. These coaxialperforations may receive bolts, screws or other mounting means wherebythe housing will be affixed to the mounting plate.

The housing also hasbosses 97 and 98.,The boss 97 has perforations 99 and 100. The perforation 99 is adapted to be coaxial with the perforation 86in the mounting plate, a similar perforation in the vat or sump (not shown) and the perforation 22 in the duct. Perforation 100 in the housing 11 is similarly adapted to be coaxial with perforation 88 in the mounting plate, a similar perforation inthe vat or sump'and the perforations 24 and 54 in the duct.

In similar manner, the boss 98 of the housing 11 has a perforation 101 adapted to be coaxial with the perforation 87 in the mounting plate, a similar perforation in the vat or sump and the duct perforation 23. The boss 98 has an additional perforation 102 adapted to be coaxial with the mounting plate perforation 89, a similar perforation in the vat or sump and the duct perforations and 53.

FIG. 11 is a cross-sectional view taken along the section line ll-ll of FIG. 1. The duct structure 13 may be considered to be sectioned along section line Ila-11a of FIG. 5. The impeller or blower housing 11 may be considered as being sectioned along section line 1 lb-l I b of FIG. 10.

In FIG. 11 it will be noted that a bolt 103 passes through coaxial perforations 104 in the vat or sump side, 86 in the mounting plate 9 and 99 in the boss 97 of the blower housing 11. It will be understood that a second bolt (not shown) will pass through a similar perforation in the sump or vat side, perforation 87 in the mounting plate and perforation 101 in the boss 98 of the blower housing. These two bolts will affix the mounting plate 9 and the blower or impeller housing 11 to the vat or sump side, in proper position. It will be noted that the halt 14. Thus, the head of the bolt 103 will lie partial! in the U-shaped area 73 of the duct half 15. The other simi ar bolt (not shown) will be accommodated in asimilar perforation in the duct gasket 76, and the perforation 23 in the duct half 14 and will lie partially in the U-shaped area 72 of the duct half 15.

The duct structure 13, itself, will be affixed in place by two substantially identical bolts, one of which is shown at 105. The bolt 105 passes through perforations24 and 54 in the duct halves, perforation 760 in the duct gasket 76, perforation 106 in the vat or sump side, perforation 88 in the mounting plate and perforation 100 in the boss 97 of the housing 11. The corresponding bolt (not shown) will pass through duct perforations 25 and 53, corresponding perforations in the duct gasket 76 and the vat or sump side, perforation 89 in the mounting plate 9, and perforation 102 in the boss 98 of the blower or impeller housing 11. Thus, these last two mentioned bolts not only hold the duct structure 13 in place but additionally affix the mounting plate 9 and the housing I] to the vat or sump side.

The integral hinge 16 will insure that the upper edge of the duct half halves are assembled in watertight fashion. The duct gasket 76 will ensure a watertight seal along the remaining edges of the duct and between the-duct structure 13 and the side of the vat or sump 7.

The impeller or blower means, within the housing 11, may take any suitable form such as a cage-type or the like. For purposes of an exemplary showing, a cage-type blower is diagrammatically indicated in dotted lines at 107. The impeller 107 is affixed to the shaft of the motor 10, diagrammatically indicated in dotted lines. The motor 10 may be mounted on the plate 9, or supported in any other suitable way.

Modifications may be made in the invention without departing from the spirit of it. For example, when the housing 11 is made of plastic or the like, it is possible to provide the bosses 91 through 98 with properly sized holes and substitute selftapping screws for the bolts mentioned above, inclusive of bolts 103, 105.

Iclaim:

1. A one-piece duct for conveying a gaseous medium, said duct comprising a front half and a rear half joined by an integral bendable portion, said bendable portion comprising a fluid-tight hinge, said halves being pivotable about said hinge to an opposed and abutted position to. form said duct, si said rear half having at least an entrance opening for said gaseous medium, said front and rear halves in said opposed and abutted position forming an exit opening for said gaseous medium, each of said halves has at least one inwardly extending projection, said projections comprising baffles in said duct when said halves are in said opposed and abutted position.

2. The one-piece structure claimed in claim 1 wherein said halves and integral bendable portion are molded of polypropylene.

3. The structure claimed in claim 1 including means for maintaining said halves in said opposed and abutting position.

4. The structure claimed in claim 1 wherein one of said halves has at least one lug thereon, one edge of said lug being undercut, the other of said halves having means defining a pocket, said pocket having an undercut edge, said lug being 

1. A one-piece duct for conveying a gaseous medium, said duct comprising a front halF and a rear half joined by an integral bendable portion, said bendable portion comprising a fluid-tight hinge, said halves being pivotable about said hinge to an opposed and abutted position to form said duct, si said rear half having at least an entrance opening for said gaseous medium, said front and rear halves in said opposed and abutted position forming an exit opening for said gaseous medium, each of said halves has at least one inwardly extending projection, said projections comprising baffles in said duct when said halves are in said opposed and abutted position.
 2. The one-piece structure claimed in claim 1 wherein said halves and integral bendable portion are molded of polypropylene.
 3. The structure claimed in claim 1 including means for maintaining said halves in said opposed and abutting position.
 4. The structure claimed in claim 1 wherein one of said halves has at least one lug thereon, one edge of said lug being undercut, the other of said halves having means defining a pocket, said pocket having an undercut edge, said lug being receivable in said pocket, said undercut edge of said lug cooperating with said undercut edge of said pocket to maintain said lug in said pocket with a snap fit whereby said halves are maintained in said opposed and abutted position.
 5. The structure claimed in claim 1 including gasket means affixed to the exterior surface of said rear half of said duct, said gasket means having at least one perforation corresponding to and aligned with said entrance opening. 